1. Field of the Invention
The field of this invention relates generally to the field of fins for water craft and more particularly toward a fin or keel that stabilizes a surfboard or other water craft laterally, vertically. The primary purpose of the instant invention is the stabilization of a surfboard or other water craft where the intended craft direction, wave direction and hydraulic lift form a critical nexus of conditions which are to be controlled and maneuvered when operating the water craft.
2. Description of the Prior Art
There are many different types of stabilizing fins and keels or rudders on the market. The present invention seeks to offer greater control in a wider range of conditions than those currently found on the market. When maneuvering water planing devices it is beneficial to utilize a steering mechanism of some sort. Traditional methods of maneuvering and steering water craft typically involve a propulsion system and a steering system. The steering system benefits from physical engineering aspects, such as the manipulation and control of vertical lift and horizontal tracking combined with craft characteristics that effect aspects of control, such as buoyancy, rail or edge shape and bottom aspects like rocker, flat, concave or convex attributes.
Some water crafts achieve propulsion from a pull type propulsion force. Sail boarding, sailing, wakeboarding, water skiing, wind surfing and kite surfing are examples of this). Other water crafts utilize push type propulsion forces. Surfing and motor boating on waves are examples of this. Each type of propulsion system benefits from different combinations of craft and fin, or keel characteristics that work together to achieve the most desirable maneuverability. Craft speed and direction in relation to the propulsion direction combine with occupant weighting to the fore, or aft, left (starboard) and right (port) as well as relative pitch or angle on the water surface provide necessary inputs to optimal craft and occupant ride. The maneuverability of water craft depends on the direction of propulsion, the force of propulsion, the plane of the water surface, the pitch and direction of water craft, i.e., the edges, bottom profile, rocker and keel/rudder/fin.
The instant invention seeks as its primarily application for use on surfboards and high performance windsurfing boards. However, it is understood that it can be used on any water planing water craft or device. Persons who engage in floating and sliding water sports seek maximum control over their craft in a variety of conditions. Surfboards, of all of the common types of water craft, operate in the most dynamic and rigorous conditions. Accordingly, for illustration purposes, this application will be directed by way of example to the dynamics of steering a surfboard in the most critical of conditions, i.e., slow and mushy or hollow and fast waves. Nonetheless, the benefits described herein apply to different effect to all other water craft.
Three primary attributes that traditional steering mechanisms for water craft focus on are drag, stall and lift. Stall is a commonly used term in surfing and windsurfing where the rider of the water craft wishes to significantly alter the course of their water craft and a condition exists where there is not enough momentum and leverage to complete the desired course correction. Stall often ends the ride on the wave via the wave continuing on with the rider falling into the water, or otherwise impairs an ideal ride on the wave. Stall can also have other and very dangerous consequences for riders. Stall can be used to describe the situation where a water craft's momentum down the face of a wave is overcome by significant upward thrust of waves, called hydraulic lift. When the forward momentum is overcome by the force of the hydraulic lift and stall occurs, it can send the board reeling in the circular path of the dominant force of the wave as it crests and breaks. A rider in the path of a reeling board driven by the wave and the thousands of pounds per square inch that is possible when waves crash can be lethal. Minimizing board stall, accordingly, has many advantages to the rider.
The instant invention assists in steering and maneuvering water craft with increased effectiveness in both slow and mushy waves as well as in steep an fast ones. Various types of water craft in need of steering mechanisms can benefit from the device of the instant invention. Surfboard and wind surfboards benefit the most and so those types of water planing devices will be the focus of this disclosure. The benefits are realized, however, in many of the otherwise mentioned planing devices.
The ability of prior art mechanisms to overcome or minimize forces creating drag and stall are sufficient, but they miss out on potential benefits in many circumstances.
The problem with some prior art designs is the drag involved with the shaft, which is difficult to overcome. Bolen has several patents (U.S. Pat. Nos. 6,106,346, 6,379,204, 6,767,266, 6,217,402) utilizing a fin that has planar elements on top of and on the bottom of a cylindrical fin. These planar elements serve to increase drag and reduces lift. The instant invention removes the problematic elements of these inventions to provide for improved performance. U.S. Pat. No. 6,089,935 to Fleming III does not have a cylindrical mounting surface that is found in the instant design, i.e., there is no top to the fin. Fleming discloses a cylindrical bottom which is the point that actually adds drag. The instant invention contains the majority of the surface focused where the board meets the fin. U.S. Pat. No. 6,955,577 suffers from similar limitations found in Fleming. U.S. Pat. No. 3,103,673 to Martin has a planar element and uses a tilt that is downward at the fore and aft angles toward the ski. This creates significant drag and holds the ski down in the water. The instant invention operates to create lift and angles the cylinder in the opposite direction from Martin. U.S. Pat. No. 3,089,157 to May suffers from similar limitations described herein. The object of the instant invention is to provide a water planing device that reduces drag and increases lift, something that all of the prior art has failed to do.
To a large extent, the designs of steering mechanisms for water craft have not evolved much. Standard fin designs utilize a dorsal-type fin, which primarily works with the agency of propulsion referred to as drift. To understand, one can visualize a tuna swimming and using its tail fin for thrust or propulsion (back and forth motion). A tuna uses its dorsal and pectoral fins to control vertical and horizontal steering, while mainly using its tail for propulsion. Standard surfboard steering is achieved through a dorsal style fin or fins and vertically oriented tail fins. These surfboard fins offer very little in terms of positive effects on lift. Furthermore, their rigid straight line construction with its perpendicular orientation to the board actually is a hindrance to some aspects of performance. This hindrance appears in its effect on draft, stall and low-lift.
It is the object of the instant invention to provide an improved device to place on the bottom surface of water planing devices in order to overcome the shortcomings of the prior art. The instant invention provides lift and reduced stall by approximately mimicking cetaceans or dolphin and whale tails, or bat rays/manta rays, and bird wings; rather than shark, tuna, or dolphin tail/dorsal fin combinations.